mei-1, a gene required for meiotic spindle formation in Caenorhabditis elegans, is a member of a family of ATPases.

Meiotic spindle formation in the female germline of Caenorhabditis elegans requires expression of the gene mei-1. We have cloned mei-1 by transformation rescue and found that it resides near a hot spot for recombination, in an area of high gene density. The highest levels of mei-1 mRNA accumulate in the female germline of adult hermaphrodites as well as in fertilized embryos. The message persists for several hours after the protein functions in embryos, implying the need for post-transcriptional regulation. Two alternatively spliced messages are made that would result in proteins that differ internally by three amino acids; the larger of the two mRNAs is preferentially enriched in the female germline. The sequence of mei-1 shows that it is a member of a newly described family of ATPases that share a highly conserved nucleotide-binding site; four dominant-negative mutations of mei-1 are found at or near this region. Divergent roles ascribed to this family include membrane function, proteolysis, transcription and cell cycle regulation.